Avalanche Forecast

Issued: Feb 27th, 2018 4:46PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs.

Avalanche Canada jlammers, Avalanche Canada

Strong winds will drive the avalanche danger in many areas. The best and safest riding may be found in lower elevation sheltered terrain.

Summary

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

Wednesday: Overcast skies with light flurries / Moderate to strong southwest winds / Alpine temperature of -12Thursday: 5-10cm of new snow / Moderate southerly winds / Alpine temperature of -7Friday: Overcast skies with light flurries / Light and variable winds / Alpine temperature of -10

Avalanche Summary

No new avalanches were reported on Monday. On Sunday several storm slab avalanches to size 2.5 occurred in response to new snow and wind. The avalanches failed on all aspects above 1800m. Continued wind and snowfall will promote ongoing wind slab activity. Although deeper, persistent avalanche activity has become less frequent over the past week, light triggers in shallow rocky areas, as well as large triggers such as a cornice collapse or step down from a wind slab release, still have the potential to result in large destructive avalanches.

Snowpack Summary

Since Saturday night, 20-50 cm of new snow fell. These accumulations cover old surfaces which include faceted powder, a sun crust on solar aspects and surface hoar on shaded, wind-sheltered slopes. I suspect strong winds will have redistributed much of the new snow into fresh wind slabs in exposed terrain.30-65cm below the surface lies another interface, with similar character and distribution that was buried mid-February. This layer has produced large avalanches in the neighbouring North Columbia region, and is definitely worth keeping an eye on as the overlying slab gains thickness and cohesion.Within the mid and lower snowpack are several persistent weak layers that are slowly beginning to show signs of improving but still remain suspect as low probability - high consequence avalanche problems. Two surface hoar/ crust layers buried in January are now 100-150 cm below the snow surface. At least one of these layers can be found on all aspects and elevations. Deeper in the snowpack (150 - 200 cm deep) is a facet/crust/surface hoar layer buried in December. Near the base of the snowpack is a crust/facet combo layer buried in late November.

Problems

Wind Slabs

An icon showing Wind Slabs
New snow and continued strong winds will create wind slabs in many areas in the alpine as well as open areas at lower elevations. If triggered wind slabs may "step down" to deeper layers including a weak interface buried mid-February.
Make observations and assess conditions continually as you travel.Be cautious as you transition into wind affected terrain.Stay off recent wind loaded areas until the slope has had a chance to stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 28th, 2018 2:00PM